i totally agree with dina. You want to wear light-weight breezy, breathable,
non-constricting, loose fitting capris or gauchos during the day, especially when you are on the islands. Save the denim skirts & capris for Casual nights on the cruise
Linen and lightweight cotton fabrics.

I bought lots of light-weight, lounge-ish type capris and gauchos, and I'm also taking denim skirts and capris.

Will I be miserable?

Everybody has a different comfort level, but I doubt that you will be any more miserable than if you wear the same clothing at home on a summer day. If you are going to a warm destination, light cotton sun dresses might be a better option.

I bring several long light weight summer Hawaiian type skirts. I pair them with light weight tops, sleeveless or otherwise. They can have an open pleat in back or on the sides. I wear them with sandals or little heels. Simple or flowered...doesn't matter. I feel comfortable, they are packable...don't wrinkle.